/**
 * Copyright (C) 2007, 2008 Carnegie Mellon University and others.
 *
 * This file is part of Plural.
 *
 * Plural is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Plural is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Plural; if not, see <http://www.gnu.org/licenses>.
 *
 * Linking Plural statically or dynamically with other modules is
 * making a combined work based on Plural. Thus, the terms and
 * conditions of the GNU General Public License cover the whole
 * combination.
 *
 * In addition, as a special exception, the copyright holders of Plural
 * give you permission to combine Plural with free software programs or
 * libraries that are released under the GNU LGPL and with code
 * included in the standard release of Eclipse under the Eclipse Public
 * License (or modified versions of such code, with unchanged license).
 * You may copy and distribute such a system following the terms of the
 * GNU GPL for Plural and the licenses of the other code concerned.
 *
 * Note that people who make modified versions of Plural are not
 * obligated to grant this special exception for their modified
 * versions; it is their choice whether to do so. The GNU General
 * Public License gives permission to release a modified version
 * without this exception; this exception also makes it possible to
 * release a modified version which carries forward this exception.
 */
package edu.cmu.cs.syncorwim.simple.provider;

import edu.cmu.cs.crystal.annotations.PassingTest;
import edu.cmu.cs.crystal.annotations.UseAnalyses;
import edu.cmu.cs.plural.annot.ClassStates;
import edu.cmu.cs.plural.annot.Full;
import edu.cmu.cs.plural.annot.State;
import edu.cmu.cs.plural.annot.States;
import edu.cmu.cs.plural.annot.Use;

@PassingTest
@UseAnalyses("SyncOrSwim")
@States({"OPEN", "CLOSED"})
@ClassStates({@State(name="OPEN", inv="f_1 == true * f_2 == false"), 
	          @State(name="CLOSED", inv="f_1 == false * f_2 == true")})
public class TwoSyncIsOkay {

	@SuppressWarnings("unused")
	private boolean f_1 = true;
	
	@SuppressWarnings("unused")
	private boolean f_2 = false;
	
	// Not sure why you would do this except by accident, but
	// our analysis is designed to work in this case so let's
	// make sure that it actually does. *Note that the method
	// itself is synchronized, which is what makes this test
	// interesting.
	@Full(use = Use.FIELDS, requires="OPEN", ensures="CLOSED")
	synchronized void close() {
		synchronized(this) { 
			f_1 = false;
		}
		
		synchronized(this) {
			f_2 = true;
		}
	}
}